Electric motor mechanism



Mays, 1930. M EA 1,757,840

ELECTRICy MOTOR MECHANISM Filed July 19, 1924 Patented May 6, 1930UNITED STATES JOHN M. LEA, F DETROIT, MICHIGAN ELECTRIC MOTOR MECHANISMApplication led Ju1y,19, 1924.` Serial No. 726,992. y

The invention relates to` electric motor mechanism of the type in whichan electromagnet is utilized to effect reciprocating movement of amember to be actuated. Preferably, the electromagnetic means is arrangedto effect the movement of the member in one direction only, the returnmovement being produced by a spring or springs in which energy is storedduring the active or working v stroke of the electromagnet. While insome respects of more general application, the invention has been foundof particular utility in connection with, and will be herein describedas embodied in, the actuating'` mechanism of a pumping device adapted tosupply liquid fuel to the carbureter of an internal combustion` engine'.The pump herein disclosed includes an eX- pansible chamber, preferablyof the metallic- 3o ed by spring means while the suction or intakestroke is effected directly by the electromagnet. l A

The object of the invention is to improve the construction and operationof devices of the class referred to and to this end it includes variousfeatures of the electromagnet and its control devices and of the partsrelated thereto, all as hereinafter described in detail and set forth inthe appended claims. I

In the accompanying drawings, illustrating one embodiment of theinvention, Figure 1 is a vertical sectional view showing the inventionas applied to a fuel pump for an internal combustionengine of anautomobile, the scale being, greatly enlarged in order to show the partsmore clearly;

Figure 2 is a top plan view of the structure shown in Figure 1 but ona-reduced scale;

Figure 3 isa horizontal section on line 3-3 of Figure 1; i

,Figure 4 is a vertical section on line 4.-4 p of Figure 3 showing apart of the structure also on an enlarged scale;

Figure 5 is a section on line 5--5 of Figure 3, showing part of thestructurev and also a wiring diagram; and,

Figure 6 is a perspective view of a valve spring forming a detail of thepump mechamsm.

Referring to the drawings, 7 indicates a head or top plate formed, onits upper side, with a central boss 8 having within it the internallyscrew-threaded rrecess 9. Extending laterally from the boss 8 areenlargements 10, 11, in which are formed respectively the inlet Ipassage 12 and outlet passage 13. These passages are provided with screwthreads, as at 14, 15, to adapt them for the attachment of suitable pipefittings. The upper end of the recess 9 is closed by a screw cap 16adapted to engagel the screw threads on the interior of the recess. Thecap is hollow to provide an air chamber 17. An` orifice 18 extendsthrough the lower face of the plate 7 communicating with the recess 9but of-somewhat smaller diameter thus providing a shoulder above theorifice.

Between the shoulder' around the orifice 18 and the lower end of thescrew cap 16 is ositioned a flange 19 of a valve casing member 20. Ifdesired, a screen 21 may be positioned at the inlet end of the valvecasing, the periphery of the screen being formed to rest upon theflange-19 and beneath the lower end of the screw cap 16.

It will be seen therefore that the valve casing 20 and screen 21 areinsertable and removable through the recess 9 from the upper or outerside of plate 7 and are retained in assembled relatlon by the screw cap16. The soft gasket 22, positioned beneath the flange 19, and hardergasket 23, between the screw cap 16 and the top of the boss 8, serveboth to seal the respective joints and to permit some tolerance in thedimenisons of the parts. Openings 211 in the lower edge of the screw cap16 permit fiow of liquid from the inlet passage 12 to the chamber 17 andthe interior of the valve casing 2Q.

The lower end of the valve casing 20 is bent 100 inwardly or upwardlyand centrally a rtured at 240. The lower orl outer face o the casing issuitably ground or polished to provide a seat with which a disk valve'25engages when in closed position. The valve is housed Within a retaimngcap 26 centrally apertured tends to maintain the valve normally inclosed position. *In the assembly of the parts the valve spring isplaced in the retainer with the valve 1n position thereon. The retaineris then pushed over the lower end of the valve casing 20 until thespring arms or clips 28 seat in the indentations 29. Thus the structurepermits Lofassembly or of removal for ection or repair with the greatestfacility.

mmunicatmg with the outlet passage 13 'u and extending 'to the lowerface of the plate 3o 7 is anv opening 35 in which is secured in anysuitable manner as by 'a pressed fit, a sleeve 36. This sleeve is formedat the upper end with the inwardly directed flange 37 ,which provides avalve seat on its upper lface for the disk valve 38. "A valve spring39'f1ts closel in a recess '40 in the screw cap 41 in= serte in anopening 42 inthe vupper side of theenlargement 11. The lower'end ofthespring 39 seats over a boss 43 centrally located on the valve" disk 38.The opening movement of the valve is limited and its lateraldisplacement prevented by engagement with the downwardly extendingsleeve 44 of the screw cap 41. i

Secured to the lower face of the top plate 7 and extending over both theinlet opening 18 Yand the discharge openingisabellowsmember 45. Theupperend section of the bellows I member may be fixed to the plate iny anysuitable manner asby the rin 46,v a gasket 47 .bef positioned between te up 'r faceof 'thtlansgection and the lower face o the late.

The body portion of the bellows'mem r is formed' of a series of rings48, 49, which may -the outer edge o inner The lian at'the inner edge ofring 48 ts inside the iiiige at the inner edge of, ring 49, andsimilarly the flange at the' ing, and the bellows/member' thusconstituted at 27 and having spring arms 28 engageable be stamped fromthin sheet' metal, .with outwardly directed flanges at their outer vand1s not only very simple in structure and l5 manufactured and assembledbut is of very" great durability. The last or end section of the bellowsis constituted by a plate 50 which, of course, closes the end of thebellows and forms an end wall by the actuation of which the expansiblechamber within the bellowsmay be caused to expand or contract.

comprises a solenoid and an armature 61.

The actuating mechanism for .the bellowsl The solenoid is wound upon thecore 62 bee tween the washer 63 at the lower end and the .head plate 64of insulating material, such as liber. Upon the upper face of plate 64is positioned a field latef65 of magnetic material. This plate is ormed,as shown in Figures 3 and 4, with wings 66 which lie under the armature61 and constitute a part of the magnetic circuit of the` solenoid. The'plate 65 also carries an L-shaped extension 67 between whichv and thebody of the plate the armature 61 is pivotally supported. p

e 'supporting means comprises two balls 68 seated in holes 69 in theplate 65 and upon which the lower face of the armature rests. A singleball 70 positioned between the upper face of the armature and the lowerface of the extension'67 provides a third point of support. The ball 70is held in position by a spring retainer 71 having a depression 72 inwhich the ball is seated. The retainer is prevented from lateraldisplacement by the engagement of the end remote from the ball aroundthe stud 78 and by an intermediatel point of support constituted by aprojection 73 seated in a depression of the armature. The bearin meansdescribed provides a very simple gorm of antifriction supmrt for thearmature whereby it is permitte to reciprocate with minimum loss ofenergy due to bearing friction. It is particularly effective inresisting side strains on the armature and thus cation.

The field plate 65 and the insulating plate 64 are secured tothe topplate 7 b kscrews 75 vand 76, the latter being utilized7 also as a partof the electric circuit as hereafter defscribed. Spacing sleeves 77surround the screws and rest at. theirends respectively 'against thering 46 and the plate 65. The e ectromagnet and the part-s connectedtherewith are-'thus supported ixedly from the top plate 7.

The armature 61 is connected to the end wall-50 of the bellows member bymeans of the s tud 78 which is secured to the end wall in any suitablemanner as by riveting. This pin extends loose -armature and is endv toreceive a nut 80. The armature rests' upon the upperl .endjof this nut^and, lwhen atpreventing any displacement laterally of the planeoferecipro-v 74 in the'upper face through a hole- 79 in thew-threaded atits lower tracted by the' solenoid, acts to pull the pin downwardly andthereby expand they bellows.'

may be supplied in part by the initial set given the bellows itself. ltis preferred however to utilizetthe additional energy supplied by acoiled spring 81 housed within the core 62 and engaging at its upper enda flange 82 on the lower end of the nut 78. rlhe lower end of the spring1s seated tightly in a recess 83 in the screw 84 engaging the screwthreaded interior of the core 62. By the tight iit of the spring 81within the recess 83, and similarly of the spring 39 within the recess40, the springs are automatically retained in proper position forassembly which operation is thereby materially facilitated, and loss ormisplacement is obviated.

The pump and its actuating mechanism are wholly enclosed by the casing85 which is cup-shaped with an aperture in the bottom through which thescrew 84 extends. The casing seats directly on the end of the core 62and is clamped in that position by the screw 84. The upper edge of thecasing fits within a peripheral Bange 86 on the top plate 7 and isthereby held from lateral displacement relatively to the top plate andthe parts supported thereon. The casing, which is of magnetic material,forms part of the external metallic circuit for the lines of forcegenerated by the electromagnet. For this reason it is very close to theperipheral edge of the plate 65, also of magnetic material, and whichalso forms part of the external circuit. The armature 61, which is asubstantially flat plate pivoted near one edge, bridges the the core 62and the plate 65 with its wings 66.. lt is therefore so positioned as toutilize V:most efiiciently the magnetic energy in eiecting the slightmovement toward the core necessary for the actuation of the pump.

The supply of electric energy to the winding 60 of the electromagnet maybe edected by the means shown in part in section and in partdiagrammatically in Figure 5. ln the arrangement illustrated, aconductor 90, leading from a suitable source of electricity as thestorage battery 91 of the automobile, terminates in a connector 9 2.This connector is provided with depending flanges 93 which engage thesides of a square nut 94 to which the connector is clamped by a screw95. The nut is seated at its lower end in a square block of insulatingmaterial 96, positioned in a square depression in the top plate 7, andrests upon an insulating washer 97 whereby it is insulated from the topplate. The flanges 93 prevent rotation of the connector on the nut andthe block 96 prevents rotation of theY nut on the top plate.' A sleeveofinsulating material such as a piece vof rubber tubing, may be placedover the connector 92 and nut 94 to prevent external objects 'fromcontacting with the bare conducting parts. The screw 7 6',

which'also'serves asone of the screws for securing the insulatingfplate64 andthe parts carried thereby tothe top plate 7 engages in the lowerend of the nut 94 and is therefore in electrical connection with thesource 91. The spacing sleeve 98 is insulated from the screw by thesleeve 99 and rests at its lower end upon the metal washer 100 whichserves to support the spacing sleeve upon the insulating washer 101.

A fixed contact support 102 is clamped between the washer 101 and theend plate 64 of the electromagnet. This contact support is connected toone end of the winding 60 and carries a relatively fixed Contact member103.

The relatively movable contact member 104` which is adapted to engagethe fixed contact 103 is mounted upon a support 105 of spring materialwhich extends entirely across the armature 61, lying in a slightindentation therein, and is secured at its'extreme end to the lower faceof the armature asyby riveting and soldering. Adjacent to its mid pointthe contact support 105 is apertured to provide for the passagetherethrough of the nut 80 and to the edge of the aperture is secured asleeve 106 of magnetic material. This sleeve loosely surrounds the nut80 and extends at its lower end slightly within the upA per end of thecore 62. Owing to the position of the magnetic sleeve 106 with referenceto the core and to the armature the flow of current through the windingof the electromagnet causes the sleeve to be drawn toward the armaturethereby flexing the spring support 105 and causing the contact 104 to beheldzin engagement with the contact 103 during a predetermined intervaluntil the armaturen in its downward movement engages with the supportand forces the contacts' to separate. Since the end of the springsupport 105 is secured to the armature it will be seen that the downwardmovement of the armature will iex the spring in such manner as to giveit a tendency to move downwardly in opposition to the attraction exertedupon the sleeve 106. When, therefore, the

movement of the armature brings it into engagement with the sleeve andthereby causes separation of the contacts or when the exing of thespring becomes suilicient to cause it to overcome the magneticattraction exerted upon the sleeve 106 the tension in the spring supportwill be such as to eect a quick break or snap action in the separationof the contacts. It will be noted that the contacts are set at a slightangle with reference to the direction of relative movement,therebyl'providing for a slight wiping engagement.

The contact support 105 is grounded through the armature 61 and thebellows member, which latter is in electrical connection through thering 46 and fastening screw therefor with the top plate 7. The latter,when used on an automobile, is grounded through the pipe connections tothe machine frame. -To increase the efliciency of the connections Iprefer to join the armature di- Vrectly to the pump bellows, as by thespring eneath the head of the screw 76 and in electrical connectiontherewith. The energizing circuit' can be traced from the source 91through conductor 90, connector 92, nut 94, screw 76', and plate 107 tothe Winding 60, thence through support 102, conta'cts 103, 104, support105, and intervening parts to the top plate 7.

In order to prevent undesirable sparking upon separation of the contacts103, 104, by

reason of the self-induction of the winding 60, I have devised a meansto counteract the building up of potential in the 'winding at the momentof breaking the circuit. Such means is particularly 'desirable indevices Where a low-resistance coil is arranged to receive acomparatively heavy current, and Where such devices are used in acircuit supplied for example, by a storage battery, and in which thereare no other inductive devices, in which case the power factor iscontrolled by said device. It comprises a conductor arranged preferablyin a series of turns and adjacent to the winding 60, thecounter-inductive effect varying with the resistance of the conductorand thenumber of turns. In

' order to reduce the loss of electrical energy in the device to anegligible amount and still reduce the sparking to a point where it isnot objectionable, I have found it preferable to use for the conductor acoil of wire considerably finer than that of the winding 6 0 and ofsubstantially the same number of turns. This counter-.inductive windingis represented on the drawing at 108 and may be wound directly under orover the winding 60. Its ends may be connected to each other in anysuitable manner but, for convenience, I have used the outside windingand connected the ends to plate 107 to whiph the one end ofthe winding60 is also co ected. This closed or short circuit coil takes the placeof or renders unnecessary the usual form of commercial condenser and ismuch cheaper and more effective as well as simpler and more convenientfor manufacture and assembly. It will be understood that the make andbreak device may be located as shown or at any other point in thecircuit without aifecting Ytheop eration of the counterinduction coiland that v it may be operated mechanically or otherwise, including, forexample, such devices ,asV

ignition coils for internal combustion engines and like constructions.l.

Operation-When the pump chamber is empty and supply of current to theelectromagnet is interrupted, the armature will be oined to a plate 107.This plate is clampedheld by spring action in its upper position,

the pump. chamber being thereby contracted' and the contacts 103, 104,in engagement. `It now current is .supplied to the electromagnet as byclosing the switch 109, which may be the engine ignition switch, themagnetic body` 106 will be attracted toward the armature and the lattersimultaneously drawn toward the coil, thereby expandingthe pump chamber.This movementconstitutes the intake stroke of the pump during whichliquid may flow through the passage 12 and openin 24 and 240 past thevalve 25 into the interlor of they Air trapped within the pump chamber.l chamber 17 will be somewhat raried during fore operate to continue thesuctionV effect after the closure of the valve 25 thereby rendering theow to the pump from the source ofsupply, as the main fuel tank,approximately continuous. Furthermore, the expansion of the air permitsthe armature to complete its stroke quickly irrespective of anyresistance that might ensue as a result of the inertia or frictionincident to the setting in motion of a long column of liquid.

Upon separation of the contacts 103, 104, by the movement of thearmature the pump chamber will be`placed under spring influence tendingto cause its contraction and forcing the contents out through the valvepassage ,37 past the valve 38 into the discharge passage 13. During thismovement which constitutes the discharge stroke of the pump, thepressure .upon the material being discharged will be determined solelyby the tension given to the yactuating spring or springs. The dischargepressure therefore 'remains approximately constant irrespective ofheight of lift or other conditions on the intake side. Furthemore, therate of discharge depends u on the rate of utilization 1n the system tow ich the liquid is su plied and may be determined, for example, Ey theopeningvof the float valve of a carbureter with which the pump may beassociated. The dlscharge stroke may therefore continue over claims inview of t e prior art. I clalm:

1. In an'electromagnetic actuating device,-

a solenoid, an armature therefor, a circuit for supplying. current to lsaid solenoid, a fixedl the intake or suction stroke and will therelosrequired by the language of the appended. '125V contract, a movablecontact, a support forthe movable contact actuable to break the circuitupon movement of said armature, a magnetic body connected to saidsupport and influenced by the magnetic field of said solenoid to retainthe contacts in engagement for a predetermined period and a shortcircuited coil surrounding said solenoid to reduce the E. M. F. thereinupon separation of the contacts.

2. In an electromagnetic actuating device, a member to be actuated, asolenoid, an armature therefor connected to said member, a circuit forsupp ying current' to said solenoid, a fixed contact and a movablecontact in said circuit, a resilient support for said movable contactmounted upon said armature, means for tensioning said support uponlclosing the circuit in the direction to retain the contacts inengagement, and means for moving the support in the opposite directionto separate the contacts.

3. ln electromagnetic actuating means, a solenoid, a member to beactuated, an armature connected thereto, a circuitfor supplying currentto said solenoid, a fixed and a movable contact in said circuit, aspring fixed to said armature at one end and carrying said movablecontact at the other end, and a magnetic body xed to said springintermediate its ends and so positioned With reference to said solenoidand armature that upon passage of' `current through said solenoid saidbody will tend to move toward said armature.

4. ln electromagnetic actuating mechanism, a solenoid, an armaturetherefor arranged for pivotal movement toward and from said solenoid,and a bearing support for said armature comprising anti-'frictionbearing members engaging opposite sides of the armature.

5. Reciprocating mechanism comprising an electromagnet, an armaturetherefor, and means Jfor pivotally supporting the armature comprising aplurality of balls partially embedded in the armature.

6. An armature support comprising a fixed yoke having recesses in theinner face of o-ne arm, the armature having corresponding recesses inone face, balls seated in corresponding pairs of recesses to providethereby a pivot aboutan axis passing through the balls, and a ballbetween the other arm of the yoke and the opposed face of the armature.

7. ln an electromagnetically actuated pump, the combination of areciprocating member, an electromagnet, 'an armature therefor operativeto actuate said member, contacts for controlling said electromagnet oneof which is arranged to be moved to circuit opening position by saidarmature, and magnetically actuated means for maintaining said contactsin engagement during a predetermined movement of said armature.

8. In electromagnetic pumping mechanism, a reciprocating member, anelectromagnet, an

armature therefor pivotally supported and arranged to actuatesaidmember, a pair of .contacts adapted to control said electromagnet, aspring mounted in proximity to said armature and` supporting one of saidcontacts, a magnetic body mounted upon said spring and arranged to causemovement thereof to- Ward said armature and in a direction to retainsaid contacts closed upon passage of current through said magnet.

9. In electromagnetic actuating means, the combination of anelectromagnet, a movable armature connected to the member to beactuated, contacts adapted to control flow of current to saidelectromagnet, one of said contacts arranged to be actuated by `saidarmature in such manner as to separate the contacts after apredetermined travel of the armature tovvard the electromagnet, meansfor moving the armature away from the magnet, a spring tending to movesaid movable contact toward circuit-opening position, and a magneticbody in proximity to said armature and associated With said spring, theparts being so constructed and arranged that the magnetic body is movedtoward the armature upon the passage of current through theelectromagnet thereby stressing the spring and retaining the contacts inengagement during a .predetermined travel of the armature.

l0. ln a device for pumping iiuids, a reciprocating member, a secondreciprocating member carrying electrical contact means adapted tocontrol the action of said first member, and meansfor producing amagnetic field, both of said members arranged to be actuatedmagnetically in said field, the parts being so constructed and arrangedthat the magnetic iiux tends to cause movement of said reciprocatingmembers in opposite directions.

11. An electromagnetic actuating device comprising an electromagnet, anarmature therefor arranged to be moved by the electromagnet in onedirection, a spring adapted to move the armature in the oppositedirection and to have energy stored therein during the movement of thearmature by the electromagnet, contacts for determiningthe action of theelectromagnet, and means for controlling said contacts including amagnetic body located Within and controlled by the magneticfield of theelectromagnet and arranged to hold said contacts in engagement during apredetermined travel of the armature, said armature arranged to move thesaid body during the final portion of its travel and thereb causeseparation of the contacts.

12. tructure as setforth in claim 11, the magnetic body and armaturebeing arranged to move in opposite directions under the infiuence of themagnetic iield and in the same direction When the body is actuated bythe armature to separate the contacts.

13. An electromagnetic actuating device comprising an electromagnet, anarmature therefor, a circuit for said electromagnet, contacts in saidcircuit, means for controlling actuation of said contacts, including amagnetic body and a spring, said body and armature both located in themagnetic field of said electromagnet and arranged to be moved towardeach other and in 'opposite directions by the magnetic stresses, saidspring means arranged to be tensioned by such movement and the magneticstresses acting to hold the contacts together for a predetermined periodof the travel of the p armature.

14. Structure as set forth in claim 13, said magnetic body beingpositioned to be engaged and moved by said amature after a predeterminedtravel to thereby separate the contacts.

15. An electromagnetic actuating 'device comprising an electromagnet, acircuit for supplying current' thereto, contacts in said circuit, anarmature mounted to reciprocate toward and from said electromagnet, anda magnetic member arranged to control the actuation of said contacts,said member positioned concentrically with said electromagnet and inpart Within they core thereof, and having a part rejecting from saidcore toward the said) armature and separated from the core and armature.

16. Structure as set forth in claim 15, said magnetic member beingtubular in form and the armature having a Lportion extending throughsaid member.

17. In an electromagnetic actuating device, a solenoid, an armaturetherefor, a circuit for supplying current to said solenoid, contacts forcontrolling said circuit one of which is movable relatively tothe other,means for actuating said movable contact to break said circuit,vmagnetic means acting upon said contact to retain same incircuitclosing position during a predetermined travel of sald armature,and a shortcircuitedl coil arranged` in inductive relation to saidsolenoid to reduce sparking at said contacts upon breaking the circuit.

In testimony whereof I aiix m si ature.

JOHN A.

